超声速三维进气道内激波干扰的研究

Investigations on Shock/Shock Interactions in Three-Dimensional Supersonic Inlets

关键词:  高超声速流动  箱式进气道  侧壁压缩进气道  波系结构  流场区域

Key words:  Hypersonic flow  Box-type inlet  Sidewall compression inlet  Wave configuration  Flow field

摘要:

为了为三维进气道的设计提供有用的分析数据，对高超声速和超声速来流下三维进气道内激波干扰进行了理论和数值研究。进气道模型选取“箱式”以及三面侧压进气道作为研究对象。理论分析采用了“空间降维”方法，即将进气道各个角落处的三维双楔定常激波干扰问题转换为二维非定常激波干扰问题，并利用激波动力学对其进行求解。数值验证方法利用2阶NND差分格式求解三维无粘欧拉方程，网格数量为1200多万，并采用MPI并行进行计算。该理论分析方法很好地对进气道各个角落处的激波干扰波系结构进行了判别，并得到了干扰区马赫构型三波点附近以及规则构型反射点附近的解析解，理论分析结果与数值模拟结果吻合较好。此外，针对进气道截面内各个流场区域的总压恢复系数以及压力、密度和温度进行了研究，并考虑了箱式进气道和三面侧壁压缩进气道内的流场区域的非均匀性，干扰区马赫杆后的总压损失要比其他区域高10%左右。通过研究表明，“空间降维”方法适用于进气道压缩部分，将为进气道的设计和性能评估提供一种理论分析手段。

Abstract:

In order to provide useful data for the designs of the 3D inlets， the shock/shock interactions for the three-dimensional (3D) inlets in supersonic and hypersonic flows theoretically and numerically were explored. Box-type and sidewall compression inlet were selected as the researching model. A theoretical approach called ‘spatial dimension reduction’ was used， which transformed the problem of 3D steady to a two-dimensional unsteady one and used the shock dynamics to solve it. A two-order NND (Non-oscillatory， Non-free-parameters， Dissipative) numerical scheme was used to solve the 3D inviscid Euler equations in the numerical validation， the mesh nodes were 12 million and MPI parallel computation technology was adopted in the program. The theoretical method could determine the wave configurations in corner flow of the inlet well and obtain the solution to the flow field of shock/shock interaction in the vicinity of three-point or near the reflection point， and it agreed well with the numerical results. Also， the density， temperature， pressure， and total pressure recovery coefficient of each zone on the cross-section were investigated， the non-uniformities in the flow field for box-type and sidewall compression inlet were also discussed， the total pressure recovery coefficient behind the Mach stem is about 10 percent less than other zones. It indicated the‘spatial dimension reduction’ approach was applied to the compressional part of the inlets and it would be useful to the designs and performance assessment of the 3D inlets.